In-flight auscultation during medical air evacuation: comparison between traditional and amplified stethoscopes

The aim of this study was to evaluate the capacity of a traditional stethoscope versus an electronically amplified one (expected to reduce background and ambient noise) to assess heart and respiratory sounds during medical transport.

It was a prospective, double-blinded, randomized performed study. One traditional stethoscope (Littmann Cardiology III; 3M, St Paul, MN) and 1 electronically amplified stethoscope (Littmann 3200, 3M) were used for our tests. Heart and lung auscultation during real medical evacuations aboard a medically configured Falcon 50 aircrafts were studied. The quality of auscultation was ranged using a numeric rating scale from 0 to 10 (0 corresponding to "I hear nothing" and 10 to "I hear perfectly"). Data collected were compared using a t-test for paired values.

A total of 40 comparative evaluations were performed. For cardiac auscultation, the value of the rating scale was 4.53 ± 1.91 and 7.18 ± 1.88 for the traditional and amplified stethoscope, respectively (paired t-test: P < .0001). For respiratory sounds, quality of auscultation was estimated at 3.1 ± 1.95 for a traditional stethoscope and 5.10 ± 2.13 for the amplified one (paired t-test: P < .0001).

This study showed that practitioners would be better helped in hearing cardiac and respiratory sounds with an electronically amplified stethoscope than with a traditional one during air medical transport in a medically configured Falcon 50 aircraft.